Spark-plug



W. 0. OLSON.

. SPARK PLUG.

APPLlc 6,1918. 1,335,793. Patented Apr. 6, 1920.

A 13, the lower edge of which engages a suit-.o

UNTTED sTATns PATENT orricn.

WILLIAM O. OLSON, OF CHICAGO, ILLINOIS, ASSIGNOR TO `THE MAQBMQN CHICAGO COMPANY, OF CHICAGO, ILLINOIS, A CORPORATION OF ILLINOIS. n

SPARK-PLUG'.

Application led December 16,1918. Serial No. 266,845.

vfollowing is a specication.

This invention relates to spark plugs for internal combustion engines and its object is to provide an improved plug which will produce a ribbon-like spark of full intensity and insure ignition of the maximum quantity of gas particles in the cylinder even under ad-v verse conditions.

I have found that to secure satisfactory results with the low grade of gasolene now supplied the market for automobile and other gas engines; it is essential that the electrode terminals of the spark plug should be maintained in a highly heated or substantially incandescent condition, and it is an object of my invention to provide a spark plug which will meet these requirements and produce an extremely hot and expansive spark to insure the ignition which low grade gasolene requires. p

It is also the object of my invention to provide an improved spark plug which will not become foul with carbon due to the presence of oil in the cylinder but which will produce a spark so hot and so expansive that the oil will be entirely consumed andthe terminals maintained inY a clean condition.

In the accompanying drawings illustrati ing a preferred embodiment of the inven- Figure 1 is a central sectional elevation of the spark plug; l

Fig. 2 is a similar view of the insulating core; and 1 Figs. 3-7 vare detail views of the broad terminal.

Referring to the drawings 7 is a shell having a reduced threaded neck 8 adapted for insertion in the head of an internal com# bustion engine cylinder and provided with a shoulder or seat 9 to receive the gasket 10.

The insulating core 11, preferably made of porcelain, has a shoulder 12 which engages the gasket and the core and shell are held in assembled relation by the threaded sleeve able packing ring 14. The core has a central bore 15 which vis flared somewhat at its upper end 16 and at its lower end 17 where Y Specification of Letters Batent.

Patented npr., e, 192e. i

vit opens-into the chamber 18, this chamber extending from the lower end of the core to apoint somewhat above the shoulder 12. This chamber provides the core with a comparatively thin petticoat .19 of more than usual'length.

An electrode 20, consisting of a straight rod, preferably round, having a flange 21, is arranged in the bo're 15 and chamber 18 with its flange seated against a cement filling 22 in the `flared lower end of the bore. The Hared upper end of the bore is likewise lled with cement to seal the dry air space of the v bore between the -electrode and the core. This electrode is held in assembled relation with the core by a nut 23 between which and the end of the core are disposed one or more washers 24. rl`he nut and washers are covered by a cap 25 and a terminal nut 26 is mounted' upon the electrode above the cap. This capuprotects the core from the socket .wrenches which are customarily used in tightening the spark plug in the engine and in removing it therefrom. l Y The electrode 27, which is suitably fastened ,to the shell9, is provided with an 'enlarged flatterminal 28 having a long flat edge 29 \which is disposed at one sideof the terminal 30 of the electrode 20 and extends upward-,from the lower end thereof. and in parallel relatiolnthereto. This terminal-28 is preferablyprovid'd with an opening 31 whichmay be of any suitable form, several of which are indicated in Figs. 1, 3, 4' and 5. The purpose of this opening isV to reduce the quantity of metal in the terminal so that it will heat more rapidly and to a higher degree. The lower edge 32 of the terminal-28 is'preferably inclined downward and rearward from the straight front edge 29 to the upwardly inclined rear edge 33 to form, in effect, a point 34; constituting the lowest part of the terminal, as shown in Figs. 1, 3 and 4, and in the slightly different forms shown in Figs. 5 and 7 My improved spark plug has been found in practice to produce a broad ribbon-like spark of suliicient intensity to ignite the enthe electrodes are quickly raised to substan-A tial incandescence which will preclude the accumulation of carbon thereon. The petticoat permits a considerable part of the ex'- plosion to take place in the chamber well up in the core land this not only keeps the cham?- ber free from carbon but also provides for a high degree of heat which is desirable in meeting the conditions produced by low grade gasolene, or oil, or both. The hole 31 in the broad terminal not only reduces vthe metal so that the terminal will heat up more quickly, but it also provides an opening through which the explosion gases will pass which tends to prevent the accumulation of carbon on the terminal. l prefer to stamp the electrode 27 out of a sheet of manganese nickel to' secure the best results, vbutother materials may be employed as found desirable. l

Practical commercial use of my improved spark plug has demonstrated marked superiority over-those spark plugs now in general commercial use because it provides a larger, hotter spark, like a ribbon or flame,

because it quickly heats the terminals to a high degree, and because it provides for the entire combustion of oil and therefore maintainsl the terminals in a clean condition. I have found that it works with a high degree of eficiency in the lowest commercial grades of gasolene, .that it enables the engine to be throttled to very low speed andpermits fast acceleration, that it keeps the electrodes clean and free from the accumulation of carbon, and that it .will operate satisfactorily in a cylinder which is passing oil badly.

ln the drawings l have illustrated that form of my invention which l now consider to be the preferred embodiment thereof but l know that various changes in the form, construction and arrangement of parts may be made without departing from the spirit or sacrificing the advantages of the invention, and l reserve the 'right to make. all such changes as fairly fall within the scope of the appended claims.

I claim:

l. spark plug having two electrodes, the terminal /f one of said electrodes having an extended edge arranged alongside ,and parallel with the terminal of the other electrode and a transverse opening adjacent said edge.

2. A spark plug having two electrodes,

the terminal of one of said electrodes hav- `ing" a round surface and the terminal of the other electrode having an extended flat edge arranged alongside and parallel with said round surface and also having a transverse opening adjacent said edge.

3. A spark plug having two electrodes, the terminal of one ofl said electrodes being in the form of a straight rod and the termii edge.

vof said edges.

Lasarte nal, said flat terminal having a transverse opening therein adjacent to said extended edge.

5. An electrode for a spark plug having a terminal provided with an extended sparking edge and a. transverse opening extending through the terminal and located back -of and adjacent said edge.

6. An electrode for a spark -plug having a flat angularly shaped terminal provided with a straight'extended sparking edge and a transverse opening back of an adjacent said edge.v

7. An electrode for a spark plug having a terminal stamped from a flat metal sheet and provided with an extended edge to be arranged in juxtaposition to another termi- 'nal and also having bottom and back edges downwardly inclined and meeting at a substantial point at the lowest part of the terminal. v

8. An electrode for a spark plug having a terminal stamped from a iat metal sheet and provided with an extended edge to be arranged in juxtaposition to another terminal and having an opening back of said edge.l

9. A -spark plug having two electrodes, the terminal of one of said electrodes being in the form of a straight round rod, and the terminal of the other electrode being stamped from a dat metal sheet and having an extended edge arranged alongside and parallel with said vfirst-mentioned terminal and also having an opening backY of said 10. An electrode for a spark plug `having a fiat angularly shaped terminal, the widest part of which is at its sparking edge, and a transverse opening back of said edge.

11. A spark plug having two electrodes,

-the terminal lof one of said electrodes having two angularly disposed straight edges meeting' at a-point of convergence at the extreme bottom of said lterminal and removed from the terminal of the other electrodes, and also havingy a transverse opening between its end andthe point of convergence WM. O. OLSON.

Witnesses: Y

WM. O. BELT, f M. A..Kn Dm. 

